1. Field of the Invention
This disclosure relates to a membrane-electrode assembly for a fuel cell, a method of manufacturing a membrane-electrode assembly for a fuel cell and a fuel cell system.
2. Description of the Related Art
A fuel cell is a power generation system for producing electrical energy through an electrochemical reduction-oxidation reaction of hydrogen included in a hydrocarbon-based material and oxygen supplied separately. Typical examples of fuel cells include a polymer electrolyte membrane fuel cell (“PEMFC”) and a direct oxidation fuel cell (“DOFC”). Polymer electrolyte fuel cells include a stack as the main body of a fuel cell and generate electrical energy through an electrochemical reaction between hydrogen supplied from a reformer and oxygen from an air pump or a fan. The direct oxidation fuel cell generates electrical energy through an electrochemical reaction between a fuel and oxygen supplied separately.
In a fuel cell, a stack includes several to scores of stacked unit cells, and each unit cell includes a membrane-electrode assembly (“MEA”) and a separator. The MEA includes a polymer electrolyte membrane, a pair of catalyst layers disposed on both sides of the polymer electrolyte membrane and gas diffusion layers disposed outside of the catalyst layers.